I believe blog.serverfault.com as the voice of this particular sysadmin community has strong value, with updates on how the site works overall and meta-commentary on the site itself or the overall sysadmin community at large. For that, the occasional guest post would be a good thing. So, this is Option 2 for me.
We do have a couple of active bloggers around here, so keeping a separate community blog-site fed should be doable. I'd definitely contribute.